Heating and cooling cover



L. B. DQNKLE, JR

- EATING AND COOLING COVER April 18, 1950 2 Sheets-Sheet 1 Filed Feb. 9, 1948 INVENTOR L uc/us 5.00/1: JR. I

ATTORNEY Ap 1950 i L. B. DONKLE, JR 2,504,308

HEATING AND coounc COVER med Feb. 9, 1948 2 Sheets-Sheet 2 t 1 t j l i T 3 V L, L j c g mvsmon lac/us 6. 001m: JR.

ATTORNEY Patented Apr. 18, 1950 UNITED STATES PATENT OFFICE HEATING AND COOLING COVER Lucius B. Donklc, Jr., Ithaca, N. Y.

Application February 9, 1948, Serial No. 7,265

3 Claims. 1

The invention relates to means for heating and cooling the body, and more especially to bed covers thru which a heating or cooling medium is circulated. The air-conditioning of homes and hospitals is expensive and sometimes impractical; and consequently attempts have been made to devise some form of covering capable of cooling or heating as desired, so that a person could be assured a comfortable sleep regardless of how hot or cold the room might be.

The problem has been attacked from various angles. In some cases air has been used as the fluid medium in the cover-the air having been blown thru ducts in the cover after having been previously heated or cooled by an appropriate device. In such cases the cover was rather bulky, resembling a thick comforter or a tent. In another type a flow of water was used, being forced thru a long tube embedded in the blanketthe hot or cold water being supplied from some external source. This involved a double transfer of heat, the primary heat or cold-being produced at a distance.

Attempts were also made to use the embedded tube in the same manner as the refrigerating coil of an ordinary refrigerators-expanding the refrigerant gas directly in the blanket, to cool it; and providing another tube in the blanket (being the condenser of the refrigerating system) to heat it. It will be understood that most commercial refrigerating devices are broadly heat pumps,.

having a cold and a hot end-the heat absorbed by one coil (evaporator or freezer) being expelled by another coil (condenser or heater). In the prior devices using direct action in the blanket, one coil was always used for heating and another coil was always used for cooling. This either necessitated separate blankets, or made one blanket unduly bulky by including coils that were not desired.

In the present invention the same coil embedded in the cover is used alternately either as the evaporator or as the condenser of the refrigerating system, while another coil externally located as part of the refrigerating system is used alternatively as either the condenser or the evaporator. This reduces both the external refrigerating machine and the blanket or cover used by the person to the minimum bulk, and gives a much more practical device. Another object of the invention is to provide means for controlling the amount of heat or cold supplied to the cover. Various other objects relating to the valving and the protection of the tubing will become apparent as the description proceeds.

In the drawings forming part of this specification,

Fig. 1 illustrates the apparatus as applied to a bed cover.

Fig. 2 is a cross-sectional view showing the heating or cooling coil secured within the cover.

Fig. 3 is a diagrammatic view of the mechanism by which the desired heat or cold is supplied to the cover.

Similar reference numerals refer to similar parts thruout the various views.

Referring now to Fig. l, the bed I is shown equipped with a heating-or-cooling cover 2 supplied with a working gas or fluid as will be described, thru a flexible supply conduit 3 which encases and protects the flexible tubes and thermostatic control wires involved in the system. These connect with the heat pump unit 4, which somewhat resembles the mechanism of a domestic refrigerator in its principal parts. though with a different arrangement of circuits, as will be explained in connection with Fig. 3. In general the cover 2, conduit 3 and heating-or-cooling machine 4 are similar in external appearance to various installations in the prior art, though by the present invention they can be made somewhat less bulky than has been required in the past. This reduction in bulk is due to the fact--as will become apparent-that the primary heat or cold in the new system is produced directly in the same blanket coil, without the secondary transfer involved in air or water systems, and without any counteracting coil in the blanket-factors which have expanded the size and cost of prior devices.

The multi-purpose hot-or-cold coil 5 is shown in Fig. 2 embedded in the cover 2. In one preferred form of cover the flexible tube or coil 5 is stitched at 6 to the under side of a comforter 2 filled with down, feathers or cotton 1, the outer faces 8 and 8' being of any suitable ornamental material, such as silk or rayon taffeta for example. The under side 9 of the down filled portion is preferably made of light canvas, to which the tubes 5 are sewed in place; and below this, on the under side of the tubes 5, is a layer of very light cotton blanket material I0, thru which heat or cold can readily pass. Since the tubes 5 are at any given time either all hot or all cold, no sup plementary insulation is required between them. For those that prefer it, a thick woven blanket or other heat insulating material may be used in the upper portion in place of the stuffedcomforter construction if desired. The tubing 5 is preferably of plastic or rubber or other strong and flexible material; and since the tubes are not large they do not make the cover 2 unduly heavy, particularly as only one such cover is needed.

The mechanism by which this cover 2 is supplied with either heat or cold as desired is illustrated in Fig. 3, which indicates conventionally elementswell known in the art, but connected in a novel manner. The cover or blanket 2 is shown at the top of Fig. 3, with a pair a typical circulatory circuits of the tubing illustrated, together with the protective conduit 3 covering the tubes 5 which carry the working gas or fluid to and from the cover.2. The purpose of the mechanism below is to supply the tube 5 either with hot compressed gas or fluid for heating the blanket 2 or with cold expanded gas or vapor for cooling the blanket 2. For heating the cover 2 the tubes 5 constitute the condenser of the refrigerating machine 4; while for cooling the cover 2 the same tubes 5 constitute the evaporator of the refrigeratingmachine 4.

This refrigerating machine or heat pump l will now be described. Its principal moving part is a compressor 20, preferably driven by an electric motor. Such motor driven compressors are now produced in large quantities for the domestic rei'rigerator trade, so that they are not unduly expensive and are very quiet and compact-partlcularly in the direct electrical drive rotary compressor form. They are generally connected to a radiator condenser 2i and sometimes with an oil separator 22 with a return line 23 by which oil separated from the'refrigerating gases can be returned to the compressor it again.

The radiator 25 in the present invention acts as either a condenser or an evaporator, depending on whether the blanket at the other end of the system is being cooled or heated. When the blanket or cover 2 is being cooled, its embedded coil 5 acts as an evaporator while the radiator Elects as a condenser and is hot; whereas when the blanket or cover 2 is being heated, its embedded coil 5 acts as a condenser while the radiator 2! acts as an evaporator and is cold. I

Among the other principal operating elements are a heat exchanger 25 and sometimes a liquid receiver 2Bwhen needed. The'operation of the system depends on an arrangement of piping and valves which can best be described by tracing the course of the working fluid or vapor thru a complete heating cycle and then thru a complete cooling cycle. Though it both heats and cools, the working fluid is commonly called a refrigerant," of which various forms have been 'developed for the refrigerating field.

First taking up the system when used to supply.

heat to the blanket 2, the cool vapor entering the compressor zllthru the pipe 55 after being somewhat increased in temperature by the heat exchanger 25 is compressed and thereby greatly in creased in temperature as well as in pressure-by what is sometimes termed the heat of compression. The cool vapor thus becomes a hot vapor and is carried along in the pipe 3llincidenta1ly passing thru the oil separator 22 if one is provided. The hot vapor then reaches a valving device in which the valve 3! is open and the valv 32 is closed, as is also the valve 62.

For convenience in tracing the flow, all valves marked H are open when heating the blanket and closed when cooling it; while all valves marked C are open when cooling the blanket and closed when heating it. With this in mind, we shall return to the flow of the working fluid. The hot vapor from the pipe 30 passes thru the open valve 3| and along the pipe 33 which con- A changes are made in the how of the wor 4 tinues into the tubing 5 in the conduit 3 leading into the blanket or cover 2. A temperature or pressure gage 34 may be attached to the pipe 23. The hotvapor passing thru the tubing 8 in the blanket 2 gives on some of its heat and finally emerges as a merely warm liquid to flow back in the return direction thru the tube in the conduit 3 to the return pipe 35.

This return pipe 35 leads to a second group of valves shown at the bottom of the diagram, in

which the valve 40 is open and the valves M and 42 are closed. This sends the merely warm liquid thru the pipe 43 to the heat exchanger Zinetimes passing thru a sump or liquid receiver when needed; and the heat exchanger cools the uid so that it reaches the expansion valve til as a cool liquid refrigerant under pressure. In passing thru the expansion valve 56 the pressure is sud= denly dropped andthe temperature also drops to a refrigerating condition in accord with the well known principle of thermodynamics. The resulting cold liquid or vapor mixture flows on thru the open valve 5i to the pipe 52 which leads to the radiator 2i.

Since this radiator 29 is exposed to the ambient air of the room, it is warmer than the cold vapor and so acts as an evaporator to transfer heat from th room into the cold liquid or vapor, thus further vaporizing itwhile at the same time the vapor somewhat chills the radiator ii. The radiator 2! is therefore cold when the blanket 2 is warm.

The cold vapor passes on thru the open valve 53 to the pipe 5% leading thru the heat exchanger 25. This cool vapor there cools the warm liquid flowing into the exchanger 25 from the pipe 413 as described, while at the same time the warm liquid serves to increase the temperature of the cold vapor coming in thru the pipe 5%. After this exchange of heat, the vapor now somewhat increased in temperature passes thru the pipe 55 to the compressor 28, which returns usto the place from which we bagan to trace the circuit.

Such a, mechanism if uncontrolled might tend to overheat the blanket; and in order to regulate the amount of heat, a by-pass valve 5t is provided, which may be adjusted to short-circuit as much of the working fluid as necessary in order to maintain a comfortable temperature. This affords an easily controlled temperature regulation without varying the speed of the compressor which is often driven by an induction motor not adapted to speed regulation.

It will thus be seen that when the flow of the working fluid is in a certain direction the device will operate to warm the-cover 2 if desired. the other hand, to cool the cover 2 Cw fluid as will now be described.

Starting again from the compressor 28-whose by-pass valve to is now closed-the warm vapor entering from the pipe 55 is compressed and forced on thru the pipe till-incidentally passing thru the oil separator 22 if one is provided. The pipe 30 leads to the valving device at the upper part of the general heat pump mechanism 4 illustrated in the diagram, and now in this valving device the valves 3| and 5| are closed and the valve 32 is open. This leads the hot compressed vapor thru the pipe 52 to the radiator 2|, which being cooled by the air of the room now acts as a condenser, giving off heat and condensing the vapor to liquid form. Thus condensed to a warm liquid, the working fluid passes on thru the pipe 75 to the valving device shown at the bottom Ol.

a the diagram, where the valve 42 is open and the valves 40 and 53 are closed. This sends the warm liquid to the heat exchanger sometimes passing thru a liquid receiver 26 if desiredand in this heat exchanger 25 the liquid is cooled as will be described and then passed to a constant pressure expansion valve 50. The sudden drop of pressure thru this valve creates a corresponding drop in temperature, so that the resulting cold vapor and liquid mixture becomes a refrigerating medium, which passes on thru the open valve 62-the valves 3! and 5| being closed. The cold mixture then flows out thru the pipe 33 and the flexible tubing 5 in the conduit 3 to the blanket or cover 2, where the flexible tubing 5 being embedded in the blanket 2 serves to cool it. Under these conditions the tubes 5 serves as an evaporator instead of a condenser, and draw heat out of the blanket and surrounding air. In this case the amount of cooling is regulated by the expansion valve 50, since different pressure. drops correspond to different temperatures; and since the valve 50 tends to maintain a constant pressure drop wherever set, the amount of cooling can also be maintained constant.

' The cool vapor leaving the blanket 2 thru the flexible tubing 5 is carried to the pipe which leads to the valving device shown at the bottom of the diagram, in which the valve 4 IV is now open and the valves 40 and 53 are closed. This sends the cool vaporthru the pipe 54 to the heat exchanger 25, where it cools the warm liquid from the pipe 43 as previously mentioned. The vapor from the pipe 54 is thus itself warmed, and passes as warm vapor thru the pipe 55 to the compressor 20, from which point we began this tracing of its course.

It will thus be seen that by using the same identical coils in the blanket alternatively as either the condenser or the evaporator of the system, the apparatus is reduced'to a minimum bulk or weight so far as the body is concerned; while secondary transfers, or additional counteracting coils on the blanket are avoided. This tends to increase the comfort of the person using it and extend the practical use of such covers.

It is customary to use thermostatic controls and electrically operated valves in heating and cooling systems, and it will be understood that th various valves shown may be so operated. The 3.

.thermostatic controls and electrical wiring have been omitted from the diagram ofFig. 3 for the sake of clearness, since their application will be apparent to those skilled in the art. Such wires as may be involved in bedside controls may be conveniently passed thru the same flexible con- (i tilt 3 that carries the flexible tubing 5-from the cover 2 to the machine 4. The device is not lim-' ited to bed covers, but is also applicable to pads,

, tents, upholstery and special garments, all coming under the generalterm of cover. a

While I have in the foregoing described a certain specific form by way of example, it will be understood that it is merely for the purpose of illustration to make clear the principles of the invention, which is not limited to the particular art without departing from the scope of the invention as stated in the following claims.

Iclaim:

1. In a heating and cooling cover, the combination of a heat pump mechanism including a compressor and a'radiator, a cover to be heated or cooled, flexible tubing within said cover, a pair of conduits connecting said tubing to the heat pump mechanism to form a refrigerant circuit therewith, a valve system by which the output of the compressor may be primarily directed either to the co-veror to the radiator, the same flexible tubing within said cover then acting as either a condenser to heat the cover or as an evaporateto cool the cover as desired, a bypass around said compressor to regulate the amount of heating, and a valve in the expansion circuit to regulate the amount of cooling.

2. In a heating and cooling cover, the combination of a heat pump mechanism including a compressor and a radiator, a cover to be heated or cooled, flexible tubing within said cover, a pair of conduits connecting saidtubing to the heat pump mechanism to form a refrigerant circuit therewith, a flexible tube enclosing said conduits and extending from said cover to said mechanism,

means for insuring that the input to the comby-pass around said compressor to regulate the amount of heating, and a valve in the expansion circuit to regulate the amount of cooling.

3. In a heating and cooling cover, the combination of a compressor arranged to compress and heat a working fluid of the refrigerant type, a by-pass control around said compressor to regulate its output, a cover to be heated or cooled, flexible tubing within said cover, a radiator external to said cover and exposed to the ambient air, a pair of valves whereby the hot output from the compressor can be directed either to the flexible tubing in the cover or to the external radiator, a heat exchanger, a valve system by which the outflow from the cover and from the external radiator may be directed to said exchanger for an exchange of heat, an expansion valve for reducing the temperature of the working fluid received from the heat exchanger, and a second pair of valves for directing the cold output from the expansion valve to either the external radiator or to the flexible tubing in the cover, whereby the same flexible tubing within said cover may act either as a condenser or as an evaporator in the heat cycle of the system.

LUCIUS B. DONKLE, JR.

REFERENCES orrnn The following references are of record in the flle of this patent:

- UNITED STATES PATENTS Number Eisinger Nov. 6, 1945 

